For more than 5,000 years, a group of Ohlone Indians called San Bruno Mountain home. As hunter-gatherers, they ate shellfish, discarding the remains in piles known as shellmounds. They migrated seasonally to gather acorns and other foods, but kept a permanent encampment on the mountain's Bay side.

Two hundred and thirty-seven years after Don Gaspar de Portola's expedition brought the first Europeans to San Francisco Bay, the village of Siplichiquin is long gone, its inhabitants killed by disease or taken to Mission Dolores to serve as farm slaves for the Spanish settlers there. Yet bits of evidence remain.

"Unless you notice there are shells on the ground or know to look for fire-cracked rock along the creek, you would have no idea, really, that there was a village there for 5,000 continuous years," said Philip Batchelder, executive director of San Bruno Mountain Watch. "And yet you look all around ... and see what's happened in the last 200 years. It says an awful lot about our different relationship to the land."

Batchelder's group plans four summer hikes to explore the village remnants and the native flora the Ohlone relied on. The first trip departs Saturday morning from downtown Brisbane. The moderate, three- to four-hour hike will include a stop at the shellmound and a walk in Buckeye Canyon.

Environmentalists and contemporary American Indians worked together to maintain the ancient village, where Ohlone remains are still buried.

"When I stand on that hill - I could see the ancestors there, and they're summoning somebody for help," said Patrick Orozco, tribal chairman of the Pajaro Valley Ohlone Indian Council in Watsonville, with 300 members on its tribal roll. He believes the site could be as much as 10,000 years old.

"That mountain was something that meant a lot to the Siplichiquin people," he said.

Orozco and Mountain Watch co-founder David Schooley paired up to preserve the village. In 1997 developer SunChase G.A. California I agreed to protect the site, which actually includes two shellmounds, a main area and a smaller plot uphill that Orozco said may have been used by a shaman for ceremonies.

Myers Development, which built the Terrabay housing tracts on the mountain's South San Francisco side, also agreed to preservation. In 2004 the county and the Trust for Public Land bought about 25 acres on the eastern slope by Highway 101, where the village was. The site is now part of San Bruno Mountain State and County Park.

The land trust dates Siplichiquin to 3,200 B.C., which Batchelder said makes it the oldest of about 425 shellmound villages identified in the Bay Area. He said anthropologists found dozens of human burials at Siplichiquin, which they interpreted as evidence of hundreds of remains still unexcavated. (CORRECTION-THIS IS ONE OF THE OLDEST REMAINING SITES; THERE WERE OTHERS THAT WERE OLDER.)

Orozco said the Ohlone ate oysters, clams, abalone, crabs, sea snails and other shellfish. They piled the shells in heaps that, when ground down, are called midden.

Although few native oysters are found in the Bay today, Batchelder said the shore was suitable habitat for plenty of oyster beds before European settlement and the silting of the Bay.

Today, he said all that is left of the original Peninsula bay shore is the inland part of Shearwater in South City, a contaminated channel that runs by the Oyster Point interchange, and a bit of rock jutting out of Brisbane Lagoon.

"Ohlone" is a term for all the coastal tribelets in the greater Bay Area and replaced the Conquistadors' term "Costanoan," meaning people of the coast, in the '60s and '70s. The tribelets, with their own unique dialects, took their names from individual villages from Big Sur to the Golden Gate and from the Central Valley to the Pacific coast.

"A lot of the people today trace themselves back to the village they come from," Orozco said, adding that the word Ohlone might have come from an Ano Nuevo village at the San Mateo-Santa Cruz county border.

Ohlones are still fighting to be recognized by the U.S. government. Rather than identifying with a reservation, many have worked to preserve ancient burial sites uncovered during construction on Yerba Buena Island, in San Jose and elsewhere.

Orozco said his grandmother, Rose Rio, who shared ancient songs with him in their original language, inspired him to preserve his ancestors' culture.

"Her last words to me were, 'You have learned all that I have taught you. Now go. Teach our people the language, our stories, and this way they will know we are still here.'"

Staff writer Todd R. Brown covers Brisbane, Colma, Daly City and South San Francisco. Reach him at (650) 348-4473 or tbrown@sanmateocountytimes.com